Looks like after this the Blazers have to sign Luke for the rest of the season or cut him loose... Found this on an NBA salary cap FAQ site... Might be worth their while to trial him at (virtually) no cost...
65. What is a 10-day contract?
A 10-day contract is just that, a player contract which lasts ten days (or three games, whichever comes later). A team may sign a player to two 10-day contracts in one season (they may or may not be consecutive). After the second 10-day contract, the team can only retain the player by signing him for the remainder of the season. A team can't have more 10-day contracts than they have players on their Inactive List. Ten-day contracts are available to be used starting January 5 (or the first business day thereafter) each season.
Good luck big bird...